F*ck TSR - talk to JP at JNL Racing - he builds a lot more interesting things:
http://www.jnlracing.com/If you want something to compare with your Subaru, find a Golf Syncro, strip it and fit a turbo 16V 2.0 and Rallye drivetrain, or find a VR6 Syncro Golf3 in Germany, ship it back here and then put most of what's underneath under a Golf2 Syncro shell (higher tunnel, so much stiffer). When you realise you want more power, strap some sort of a huffer on the back and away you go.
Why in the hell would you want a FWD Golf2 with a boat anchor in the front after having an Impreza? It's like pulling a U-turn as you're running away from high servicing costs and fuel bills! The 2.0 16V should be significantly more frugal and quick enough, for some fun.
My G2 Syncro 2.0 16V weighs in at about 1060kg and will run consistant 9minute laps of the 'ring with a tool like me at the wheel - that's on a completely stock 2.0 16V ABF code motor, which got shoved in there when the old 8V went pop.
Why not look around for a built track car? You'll spend a lot less than building one yourself and with the sort of budget you're talking about you can be pretty picky.